1. Field of the Invention
The present invention relates to charging systems for motor vehicles.
2. Description of the Related Art
A typical motor vehicle with an internal combustion engine has a battery used predominantly for providing power to crank the engine to start the vehicle. Charging the battery is usually done via an alternator driven by the engine. A voltage regulator is typically mounted to the alternator and controls the output voltage of the alternator to a predetermined value. The voltage regulator contains the bulk of the electronics in a typical charging system.
An alternator generally requires a significant amount of torque from the engine. As a result, the alternator can have a detrimental effect on such engine performance parameters as idle stability and engine power. Further, there are opportunities in the control of an alternator for providing advantages, such as increased energy storage in the vehicle battery while the vehicle is being braked. Conventional charging systems simply were not designed to counteract the detrimental effects on engine performance and take advantage of opportunities available in the control of a vehicle alternator.
U.S. Pat. No. 4,659,977, issued to Kiesel et. al, discloses a charging system in which an alternator is directly connected to an engine controller. Although such a configuration may have advantages over conventional charging systems, optimal electrical system partitioning often precludes such integration. It may be preferable in some instances for a substantial amount of the charging system electronics to remain near the alternator.
As a result, an enhanced charging system with improved ability to control the alternator and which allows a substantial amount of the charging system electronics to remain near the alternator will provide advantages over the prior art.